Several designs of devices of the above-defined kind are previously known. In GB 2305205 is described a device for attachment of insulating-glass sheets. In this case, the insulating-glass sheets are subjected to a preparatory step involving positioning of members in the jointing substance between the glass sheets in predetermined places around the insulating-glass slab. Means having a configuration complementary to said members are moved into said members as the insulating-glass slab is locked (in position?). A drawback inherent in this device is that it requires preparation of the insulating-glass sheets, a feature that in addition offers less freedom as regards the positioning of the device on the insulating-glass sheet.
Also U.S. Pat. No. 5,802,799 describes a device conceived to fasten insulating-glass sheets that require a preparatory step, however without any members being provided in the jointing substance between the glass slabs. Instead, recesses are made in the jointing substance in certain predetermined places around the insulating-glass slab. In this case the device comprises means that may be slid for reception in said recesses as the insulating-glass slab is to be fixed. Consequently, this device too, enjoys less freedom as regards its positioning.
A further variety of devices for attachment of insulating-glass sheets is described in SE 514175, wherein the step of preparing the insulating-glass sheet has been eliminated. A rectangular washer, which is connected to a retainer element and which has a width equaling that of the spacing between two juxtaposed insulating-glass sheets and a length exceeding the width, is introduced between two insulating-glass sheets. The washer is then turned over approximately 90°, causing the short sides of the washer to penetrate into the jointing substance between the glass slabs and in this manner securing the insulating-glass sheet. Because the width of the rectangular element is limited by the spacing between two insulating-glass sheets, a large number of washers per unit length of insulating-glass sheet edge is required in order to obtain satisfactory attachment. In addition, it is necessary that two insulating-glass sheets, positioned adjacent one another, be secured simultaneously, which means that two insulating-glass sheets must be held in position simultaneously. As a result, the mounting of the insulating-glass sheets becomes more difficult.